The CloneTracker XP™ Expressed Lentiviral Barcode Library, and Barcoded CRISPR Library product lines feature the ability to label and trace individual cells. Together with sequencing technology, they enable a new approach for tracking clonal variations in large cell populations and can be powerful experimental tools in many research areas, including cell development and evolution, stem cell biology, or carcinogenesis. The new Barcode Libraries’ unique DNA sequence (i.e., the barcode) is designed to express on an RNA transcript in the cells. As a result, it can be detected by either DNA or RNA sequencing. A variation of the new CloneTracker XP barcode labeling product is also available that offers a gene effector, in this case, CRISPR sgRNA, into the barcode library. Each effector targets and disrupts a specific gene in each of the cells that pick up a barcode. In combination with cell-specific barcode tracking, this knockout enables researchers to see how particular genetic disruptions change the characteristics of the cells, while simultaneously also identifying the genetic pathways that are activated to produce them.